This might sound daft but hear me out? That room doesn't have its own circuit breaker does it?

Looking at that ceiling makes me think that you live in a rather old house(?). Before modern standardisation was introduced, a lot of old wiring was a hodgepodge of random wires going to some individual rooms, and later on when it came to "modernisation", it was easier to just re-trace old wiring paths for particular rooms rather that ripping the walls out for a complete job.